Fluorescent lighting support

[aphares]

Wg:
Having problem with code ref. If you don't mind copy and paste, the reference that
specifies commercial lay in fluorescent lighting to be supported separate from the ceiling
grids.

[Wgoodrich]

NONFIRE RATED SUSPENDED CEILINGS ONLY;

aphares communicated with me late night last night and found his own Code referances. He found the opposite of what he originally was told to be true. Recessed trouffer flourescent light fixtures designed to set in the tracks of a suspended ceiling if installed with clips to secure the fixture to the suspended ceiling track then no further support is required. He asked me to research the IBC [aka International Building Code] and I found no reference to refute the NEC rules that apply. However what is being said here is for nonfire rated suspended ceilings only. Read the next post concerning fire rated suspended ceilings.

However the wiring, conduit, boxes must be supported by the support wires and not the suspended ceiling. Only the recessed trouffer fluourescent lay in fixtures are allowed per the following rules to be supported by the tracks of a suspended ceiling without further support other than the earthquake type support clips securing the fixture to the suspended ceiling tracks.

See below; COPIED SECTION NEC 2002

ARTICLE 410 Luminaires (Lighting Fixtures), Lampholders, and Lamps
IV. Luminaire (Fixture) Supports
410.16 Means of Support.
(C) Suspended Ceilings. Framing members of suspended ceiling systems used to support luminaires (fixtures) shall be securely fastened to each other and shall be securely attached to the building structure at appropriate intervals. Luminaires (fixtures) shall be securely fastened to the ceiling framing member by mechanical means such as bolts, screws, or rivets. Listed clips identified for use with the type of ceiling framing member(s) and luminaire(s) [fixture(s)] shall also be permitted.

2002 NEC HANDBOOK COMMENTARY;
Section 410.16(C) provides requirements for luminaire installations where the luminaires are supported by a suspended or “hung” ceiling. Where luminaires are supported independent of a suspended ceiling, 410.16(C) does not apply.
Section 410.16(C) requires that if clips are used to support luminaires to the framing members of a suspended ceiling, those clips must be of a type listed for the application. However, the use of listed clips for luminaire support does not complete the requirements of this section. Additionally, the ceiling framing members must be securely attached to each other and to the building structure. For the support of wiring that is located within the cavity of floor-ceiling assemblies, see 300.11(A).

PERSONAL COMMENTARY;
Boxes and cables are different see below;

COPIED SECTION 2002 NEC;

300.11 Securing and Supporting.
(A) Secured in Place. Raceways, cable assemblies, boxes, cabinets, and fittings shall be securely fastened in place. Support wires that do not provide secure support shall not be permitted as the sole support. Support wires and associated fittings that provide secure support and that are installed in addition to the ceiling grid support wires shall be permitted as the sole support. Where independent support wires are used, they shall be secured at both ends. Cables and raceways shall not be supported by ceiling grids.
(2) Non–Fire-Rated Assemblies. Wiring located within the cavity of a non–fire-rated floor–ceiling or roof–ceiling assembly shall not be secured to, or supported by, the ceiling assembly, including the ceiling support wires. An independent means of secure support shall be provided.
Exception: The ceiling support system shall be permitted to support branch-circuit wiring and associated equipment where installed in accordance with the ceiling system manufacturer’s instructions.

SEE NEXT REPLY CONCERNING FIRE RATED CEILINGS !!!

Hope this helps

Wg

[Wgoodrich]

FIRE RATED SUSPENDED CEILING;

Light fixtures are not allowed to be supported by the grid of the suspended cieling if that suspended ceiling is fire rated. Place of assembly, schools, and ceiling area used as air ducting component, hazardous locations are areas where suspended ceilings can be rated as fire rated ceilings.

See the rules below forbidding not only wiring but fixtures from being supported by a fire rated suspended ceiling and not even allowed to be supported by the wires that support that fire rated suspended ceilng.


300.11.A
(1) Fire-Rated Assemblies. Wiring located within the cavity of a fire-rated floor–ceiling or roof–ceiling assembly shall not be secured to, or supported by, the ceiling assembly, including the ceiling support wires. An independent means of secure support shall be provided. Where independent support wires are used, they shall be distinguishable by color, tagging, or other effective means from those that are part of the fire-rated design.
Exception: The ceiling support system shall be permitted to support wiring and equipment that have been tested as part of the fire-rated assembly.

NEC HANDBOOK COMMENTARY;
Wiring methods of any type and all luminaires are not allowed to be supported or secured to the support wires or T bars of a fire-rated ceiling assembly unless the assembly has been tested and listed for that use. If support wires are selected as the supporting means for the electrical system within the fire-rated ceiling cavity, they must be distinguishable from the ceiling support wires and they must be secured at both ends.

Generally, the rule for supporting electrical equipment is “securely fastened in place.” This phrase means not only that vertical support for the weight of the equipment must be provided but also that the equipment must be secured to prevent horizontal movement or sway. The intention is to prevent the loss of grounding continuity provided by the raceway that could result from horizontal movement.
Sections 300.11(A)(1) and (A)(2) are quite similar. Unless the exceptions apply, these sections clearly prohibit all types of wiring from being attached in any way to the support wires of a ceiling assembly. Unless ceiling grids are part of the building structure, they, too, are prohibited from furnishing support for cables and raceways. However, if wiring and equipment are located within the ceiling cavity and rigidly supported independent of the ceiling, without the use of ceiling-type hanger wire, then the requirements of this section are met.
Refer to the appropriate wiring method article in Chapter 3 of the Code for cable and raceway supporting requirements. See 410.15(A) and 410.16 for the proper support of luminaires; 314.23 for the support of outlet boxes; and 725.6, 760.6, and 770.8 for various low-voltage fire alarm and optical fiber cable supports. See Chapter 8 for communications cable supports.


Hope this helps

Wg

[aphares]

Thanks, No other place could I get such detail

Art

[Wgoodrich]

Art

Half those details came from you in our previous conversations on that subject. You should carry the credit of that reply as much as me. I just typed it out, you said most of it in our conversations.

Wg

[RMiell]

This is all true, however the UBC, which in force here in my town, does contain language that requires the fixture to be seperately hung, and the method depends on whether or not it is a light duty, itermediate duty, or heavy duty rated grid.

Light duty: cannot support fixtures. I take this to mean support wires are required at each corner of the trouffer

Intermediate: At each corner of the fixture (within 3" of the corner), there needs to be No. 12 gage hangers attaching the grid to the structure above.

Heavy duty: Supplemental wires (for the grid only) are not required if a 48" modular hanger pattern is followed.

For the fixtures: If fixture is less than 56 lbs., there needs to be 2 No. 12 gage wires from the fixture to the structure, and these 2 wires can be slack.

If the fixture is equal to or more than 56 lbs, it needs to be supported directly from the structure above by approved hangers (ie: a No. 12 gage wire from each corner)

These rules are from Uniform Building Code, and are in Section 25.213.

Rick Miell